/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.scheduling.support;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.UndeclaredThrowableException;

import org.springframework.util.ReflectionUtils;

/**
 * Variant of {@link MethodInvokingRunnable} meant to be used for processing
 * of no-arg scheduled methods. Propagates user exceptions to the caller,
 * assuming that an error strategy for Runnables is in place.
 *
 *
 * 定时任务类(对应spring 定时任务注解的函数)
 * @author Juergen Hoeller
 * @see org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor
 * @since 3.0.6
 */
public class ScheduledMethodRunnable implements Runnable {

    private final Object target;

    private final Method method;


    /**
     * Create a {@code ScheduledMethodRunnable} for the given target instance,
     * calling the specified method.
     *
     * @param target the target instance to call the method on
     * @param method the target method to call
     */
    public ScheduledMethodRunnable(Object target, Method method) {
        this.target = target;
        this.method = method;
    }

    /**
     * Create a {@code ScheduledMethodRunnable} for the given target instance,
     * calling the specified method by name.
     *
     * @param target     the target instance to call the method on
     * @param methodName the name of the target method
     * @throws NoSuchMethodException if the specified method does not exist
     */
    public ScheduledMethodRunnable(Object target, String methodName) throws NoSuchMethodException {
        this.target = target;
        this.method = target.getClass().getMethod(methodName);
    }


    /**
     * Return the target instance to call the method on.
     */
    public Object getTarget() {
        return this.target;
    }

    /**
     * Return the target method to call.
     */
    public Method getMethod() {
        return this.method;
    }


    @Override
    public void run() {
        try {
            ReflectionUtils.makeAccessible(this.method);
            this.method.invoke(this.target);
        }
        catch (InvocationTargetException ex) {
            ReflectionUtils.rethrowRuntimeException(ex.getTargetException());
        }
        catch (IllegalAccessException ex) {
            throw new UndeclaredThrowableException(ex);
        }
    }

    @Override
    public String toString() {
        return this.method.getDeclaringClass().getName() + "." + this.method.getName();
    }

}
